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-rw-r--r--arch/riscv/kernel/Makefile2
-rw-r--r--arch/riscv/kernel/traps.c27
-rw-r--r--arch/riscv/kernel/traps_misaligned.c370
3 files changed, 395 insertions, 4 deletions
diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile
index c121cc491eb8..1bad93f63dba 100644
--- a/arch/riscv/kernel/Makefile
+++ b/arch/riscv/kernel/Makefile
@@ -30,7 +30,7 @@ obj-y	+= cacheinfo.o
 obj-y	+= patch.o
 obj-$(CONFIG_MMU) += vdso.o vdso/
 
-obj-$(CONFIG_RISCV_M_MODE)	+= clint.o
+obj-$(CONFIG_RISCV_M_MODE)	+= clint.o traps_misaligned.o
 obj-$(CONFIG_FPU)		+= fpu.o
 obj-$(CONFIG_SMP)		+= smpboot.o
 obj-$(CONFIG_SMP)		+= smp.o
diff --git a/arch/riscv/kernel/traps.c b/arch/riscv/kernel/traps.c
index 23a57b92cd1d..29aef5cbaf65 100644
--- a/arch/riscv/kernel/traps.c
+++ b/arch/riscv/kernel/traps.c
@@ -97,12 +97,33 @@ DO_ERROR_INFO(do_trap_insn_fault,
 	SIGSEGV, SEGV_ACCERR, "instruction access fault");
 DO_ERROR_INFO(do_trap_insn_illegal,
 	SIGILL, ILL_ILLOPC, "illegal instruction");
-DO_ERROR_INFO(do_trap_load_misaligned,
-	SIGBUS, BUS_ADRALN, "load address misaligned");
 DO_ERROR_INFO(do_trap_load_fault,
 	SIGSEGV, SEGV_ACCERR, "load access fault");
+#ifndef CONFIG_RISCV_M_MODE
+DO_ERROR_INFO(do_trap_load_misaligned,
+	SIGBUS, BUS_ADRALN, "Oops - load address misaligned");
 DO_ERROR_INFO(do_trap_store_misaligned,
-	SIGBUS, BUS_ADRALN, "store (or AMO) address misaligned");
+	SIGBUS, BUS_ADRALN, "Oops - store (or AMO) address misaligned");
+#else
+int handle_misaligned_load(struct pt_regs *regs);
+int handle_misaligned_store(struct pt_regs *regs);
+
+asmlinkage void do_trap_load_misaligned(struct pt_regs *regs)
+{
+	if (!handle_misaligned_load(regs))
+		return;
+	do_trap_error(regs, SIGBUS, BUS_ADRALN, regs->epc,
+		      "Oops - load address misaligned");
+}
+
+asmlinkage void do_trap_store_misaligned(struct pt_regs *regs)
+{
+	if (!handle_misaligned_store(regs))
+		return;
+	do_trap_error(regs, SIGBUS, BUS_ADRALN, regs->epc,
+		      "Oops - store (or AMO) address misaligned");
+}
+#endif
 DO_ERROR_INFO(do_trap_store_fault,
 	SIGSEGV, SEGV_ACCERR, "store (or AMO) access fault");
 DO_ERROR_INFO(do_trap_ecall_u,
diff --git a/arch/riscv/kernel/traps_misaligned.c b/arch/riscv/kernel/traps_misaligned.c
new file mode 100644
index 000000000000..46c4dafe3ba0
--- /dev/null
+++ b/arch/riscv/kernel/traps_misaligned.c
@@ -0,0 +1,370 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2020 Western Digital Corporation or its affiliates.
+ */
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/irq.h>
+
+#include <asm/processor.h>
+#include <asm/ptrace.h>
+#include <asm/csr.h>
+
+#define INSN_MATCH_LB			0x3
+#define INSN_MASK_LB			0x707f
+#define INSN_MATCH_LH			0x1003
+#define INSN_MASK_LH			0x707f
+#define INSN_MATCH_LW			0x2003
+#define INSN_MASK_LW			0x707f
+#define INSN_MATCH_LD			0x3003
+#define INSN_MASK_LD			0x707f
+#define INSN_MATCH_LBU			0x4003
+#define INSN_MASK_LBU			0x707f
+#define INSN_MATCH_LHU			0x5003
+#define INSN_MASK_LHU			0x707f
+#define INSN_MATCH_LWU			0x6003
+#define INSN_MASK_LWU			0x707f
+#define INSN_MATCH_SB			0x23
+#define INSN_MASK_SB			0x707f
+#define INSN_MATCH_SH			0x1023
+#define INSN_MASK_SH			0x707f
+#define INSN_MATCH_SW			0x2023
+#define INSN_MASK_SW			0x707f
+#define INSN_MATCH_SD			0x3023
+#define INSN_MASK_SD			0x707f
+
+#define INSN_MATCH_FLW			0x2007
+#define INSN_MASK_FLW			0x707f
+#define INSN_MATCH_FLD			0x3007
+#define INSN_MASK_FLD			0x707f
+#define INSN_MATCH_FLQ			0x4007
+#define INSN_MASK_FLQ			0x707f
+#define INSN_MATCH_FSW			0x2027
+#define INSN_MASK_FSW			0x707f
+#define INSN_MATCH_FSD			0x3027
+#define INSN_MASK_FSD			0x707f
+#define INSN_MATCH_FSQ			0x4027
+#define INSN_MASK_FSQ			0x707f
+
+#define INSN_MATCH_C_LD			0x6000
+#define INSN_MASK_C_LD			0xe003
+#define INSN_MATCH_C_SD			0xe000
+#define INSN_MASK_C_SD			0xe003
+#define INSN_MATCH_C_LW			0x4000
+#define INSN_MASK_C_LW			0xe003
+#define INSN_MATCH_C_SW			0xc000
+#define INSN_MASK_C_SW			0xe003
+#define INSN_MATCH_C_LDSP		0x6002
+#define INSN_MASK_C_LDSP		0xe003
+#define INSN_MATCH_C_SDSP		0xe002
+#define INSN_MASK_C_SDSP		0xe003
+#define INSN_MATCH_C_LWSP		0x4002
+#define INSN_MASK_C_LWSP		0xe003
+#define INSN_MATCH_C_SWSP		0xc002
+#define INSN_MASK_C_SWSP		0xe003
+
+#define INSN_MATCH_C_FLD		0x2000
+#define INSN_MASK_C_FLD			0xe003
+#define INSN_MATCH_C_FLW		0x6000
+#define INSN_MASK_C_FLW			0xe003
+#define INSN_MATCH_C_FSD		0xa000
+#define INSN_MASK_C_FSD			0xe003
+#define INSN_MATCH_C_FSW		0xe000
+#define INSN_MASK_C_FSW			0xe003
+#define INSN_MATCH_C_FLDSP		0x2002
+#define INSN_MASK_C_FLDSP		0xe003
+#define INSN_MATCH_C_FSDSP		0xa002
+#define INSN_MASK_C_FSDSP		0xe003
+#define INSN_MATCH_C_FLWSP		0x6002
+#define INSN_MASK_C_FLWSP		0xe003
+#define INSN_MATCH_C_FSWSP		0xe002
+#define INSN_MASK_C_FSWSP		0xe003
+
+#define INSN_LEN(insn)			((((insn) & 0x3) < 0x3) ? 2 : 4)
+
+#if defined(CONFIG_64BIT)
+#define LOG_REGBYTES			3
+#define XLEN				64
+#else
+#define LOG_REGBYTES			2
+#define XLEN				32
+#endif
+#define REGBYTES			(1 << LOG_REGBYTES)
+#define XLEN_MINUS_16			((XLEN) - 16)
+
+#define SH_RD				7
+#define SH_RS1				15
+#define SH_RS2				20
+#define SH_RS2C				2
+
+#define RV_X(x, s, n)			(((x) >> (s)) & ((1 << (n)) - 1))
+#define RVC_LW_IMM(x)			((RV_X(x, 6, 1) << 2) | \
+					 (RV_X(x, 10, 3) << 3) | \
+					 (RV_X(x, 5, 1) << 6))
+#define RVC_LD_IMM(x)			((RV_X(x, 10, 3) << 3) | \
+					 (RV_X(x, 5, 2) << 6))
+#define RVC_LWSP_IMM(x)			((RV_X(x, 4, 3) << 2) | \
+					 (RV_X(x, 12, 1) << 5) | \
+					 (RV_X(x, 2, 2) << 6))
+#define RVC_LDSP_IMM(x)			((RV_X(x, 5, 2) << 3) | \
+					 (RV_X(x, 12, 1) << 5) | \
+					 (RV_X(x, 2, 3) << 6))
+#define RVC_SWSP_IMM(x)			((RV_X(x, 9, 4) << 2) | \
+					 (RV_X(x, 7, 2) << 6))
+#define RVC_SDSP_IMM(x)			((RV_X(x, 10, 3) << 3) | \
+					 (RV_X(x, 7, 3) << 6))
+#define RVC_RS1S(insn)			(8 + RV_X(insn, SH_RD, 3))
+#define RVC_RS2S(insn)			(8 + RV_X(insn, SH_RS2C, 3))
+#define RVC_RS2(insn)			RV_X(insn, SH_RS2C, 5)
+
+#define SHIFT_RIGHT(x, y)		\
+	((y) < 0 ? ((x) << -(y)) : ((x) >> (y)))
+
+#define REG_MASK			\
+	((1 << (5 + LOG_REGBYTES)) - (1 << LOG_REGBYTES))
+
+#define REG_OFFSET(insn, pos)		\
+	(SHIFT_RIGHT((insn), (pos) - LOG_REGBYTES) & REG_MASK)
+
+#define REG_PTR(insn, pos, regs)	\
+	(ulong *)((ulong)(regs) + REG_OFFSET(insn, pos))
+
+#define GET_RM(insn)			(((insn) >> 12) & 7)
+
+#define GET_RS1(insn, regs)		(*REG_PTR(insn, SH_RS1, regs))
+#define GET_RS2(insn, regs)		(*REG_PTR(insn, SH_RS2, regs))
+#define GET_RS1S(insn, regs)		(*REG_PTR(RVC_RS1S(insn), 0, regs))
+#define GET_RS2S(insn, regs)		(*REG_PTR(RVC_RS2S(insn), 0, regs))
+#define GET_RS2C(insn, regs)		(*REG_PTR(insn, SH_RS2C, regs))
+#define GET_SP(regs)			(*REG_PTR(2, 0, regs))
+#define SET_RD(insn, regs, val)		(*REG_PTR(insn, SH_RD, regs) = (val))
+#define IMM_I(insn)			((s32)(insn) >> 20)
+#define IMM_S(insn)			(((s32)(insn) >> 25 << 5) | \
+					 (s32)(((insn) >> 7) & 0x1f))
+#define MASK_FUNCT3			0x7000
+
+#define GET_PRECISION(insn) (((insn) >> 25) & 3)
+#define GET_RM(insn) (((insn) >> 12) & 7)
+#define PRECISION_S 0
+#define PRECISION_D 1
+
+#define STR(x) XSTR(x)
+#define XSTR(x) #x
+
+#define DECLARE_UNPRIVILEGED_LOAD_FUNCTION(type, insn)			\
+static inline type load_##type(const type *addr)			\
+{									\
+	type val;							\
+	asm (#insn " %0, %1"						\
+	: "=&r" (val) : "m" (*addr));					\
+	return val;							\
+}
+
+#define DECLARE_UNPRIVILEGED_STORE_FUNCTION(type, insn)			\
+static inline void store_##type(type *addr, type val)			\
+{									\
+	asm volatile (#insn " %0, %1\n"					\
+	: : "r" (val), "m" (*addr));					\
+}
+
+DECLARE_UNPRIVILEGED_LOAD_FUNCTION(u8, lbu)
+DECLARE_UNPRIVILEGED_LOAD_FUNCTION(u16, lhu)
+DECLARE_UNPRIVILEGED_LOAD_FUNCTION(s8, lb)
+DECLARE_UNPRIVILEGED_LOAD_FUNCTION(s16, lh)
+DECLARE_UNPRIVILEGED_LOAD_FUNCTION(s32, lw)
+DECLARE_UNPRIVILEGED_STORE_FUNCTION(u8, sb)
+DECLARE_UNPRIVILEGED_STORE_FUNCTION(u16, sh)
+DECLARE_UNPRIVILEGED_STORE_FUNCTION(u32, sw)
+#if defined(CONFIG_64BIT)
+DECLARE_UNPRIVILEGED_LOAD_FUNCTION(u32, lwu)
+DECLARE_UNPRIVILEGED_LOAD_FUNCTION(u64, ld)
+DECLARE_UNPRIVILEGED_STORE_FUNCTION(u64, sd)
+DECLARE_UNPRIVILEGED_LOAD_FUNCTION(ulong, ld)
+#else
+DECLARE_UNPRIVILEGED_LOAD_FUNCTION(u32, lw)
+DECLARE_UNPRIVILEGED_LOAD_FUNCTION(ulong, lw)
+
+static inline u64 load_u64(const u64 *addr)
+{
+	return load_u32((u32 *)addr)
+		+ ((u64)load_u32((u32 *)addr + 1) << 32);
+}
+
+static inline void store_u64(u64 *addr, u64 val)
+{
+	store_u32((u32 *)addr, val);
+	store_u32((u32 *)addr + 1, val >> 32);
+}
+#endif
+
+static inline ulong get_insn(ulong mepc)
+{
+	register ulong __mepc asm ("a2") = mepc;
+	ulong val, rvc_mask = 3, tmp;
+
+	asm ("and %[tmp], %[addr], 2\n"
+		"bnez %[tmp], 1f\n"
+#if defined(CONFIG_64BIT)
+		STR(LWU) " %[insn], (%[addr])\n"
+#else
+		STR(LW) " %[insn], (%[addr])\n"
+#endif
+		"and %[tmp], %[insn], %[rvc_mask]\n"
+		"beq %[tmp], %[rvc_mask], 2f\n"
+		"sll %[insn], %[insn], %[xlen_minus_16]\n"
+		"srl %[insn], %[insn], %[xlen_minus_16]\n"
+		"j 2f\n"
+		"1:\n"
+		"lhu %[insn], (%[addr])\n"
+		"and %[tmp], %[insn], %[rvc_mask]\n"
+		"bne %[tmp], %[rvc_mask], 2f\n"
+		"lhu %[tmp], 2(%[addr])\n"
+		"sll %[tmp], %[tmp], 16\n"
+		"add %[insn], %[insn], %[tmp]\n"
+		"2:"
+	: [insn] "=&r" (val), [tmp] "=&r" (tmp)
+	: [addr] "r" (__mepc), [rvc_mask] "r" (rvc_mask),
+	  [xlen_minus_16] "i" (XLEN_MINUS_16));
+
+	return val;
+}
+
+union reg_data {
+	u8 data_bytes[8];
+	ulong data_ulong;
+	u64 data_u64;
+};
+
+int handle_misaligned_load(struct pt_regs *regs)
+{
+	union reg_data val;
+	unsigned long epc = regs->epc;
+	unsigned long insn = get_insn(epc);
+	unsigned long addr = csr_read(mtval);
+	int i, fp = 0, shift = 0, len = 0;
+
+	regs->epc = 0;
+
+	if ((insn & INSN_MASK_LW) == INSN_MATCH_LW) {
+		len = 4;
+		shift = 8 * (sizeof(unsigned long) - len);
+#if defined(CONFIG_64BIT)
+	} else if ((insn & INSN_MASK_LD) == INSN_MATCH_LD) {
+		len = 8;
+		shift = 8 * (sizeof(unsigned long) - len);
+	} else if ((insn & INSN_MASK_LWU) == INSN_MATCH_LWU) {
+		len = 4;
+#endif
+	} else if ((insn & INSN_MASK_FLD) == INSN_MATCH_FLD) {
+		fp = 1;
+		len = 8;
+	} else if ((insn & INSN_MASK_FLW) == INSN_MATCH_FLW) {
+		fp = 1;
+		len = 4;
+	} else if ((insn & INSN_MASK_LH) == INSN_MATCH_LH) {
+		len = 2;
+		shift = 8 * (sizeof(unsigned long) - len);
+	} else if ((insn & INSN_MASK_LHU) == INSN_MATCH_LHU) {
+		len = 2;
+#if defined(CONFIG_64BIT)
+	} else if ((insn & INSN_MASK_C_LD) == INSN_MATCH_C_LD) {
+		len = 8;
+		shift = 8 * (sizeof(unsigned long) - len);
+		insn = RVC_RS2S(insn) << SH_RD;
+	} else if ((insn & INSN_MASK_C_LDSP) == INSN_MATCH_C_LDSP &&
+		   ((insn >> SH_RD) & 0x1f)) {
+		len = 8;
+		shift = 8 * (sizeof(unsigned long) - len);
+#endif
+	} else if ((insn & INSN_MASK_C_LW) == INSN_MATCH_C_LW) {
+		len = 4;
+		shift = 8 * (sizeof(unsigned long) - len);
+		insn = RVC_RS2S(insn) << SH_RD;
+	} else if ((insn & INSN_MASK_C_LWSP) == INSN_MATCH_C_LWSP &&
+		   ((insn >> SH_RD) & 0x1f)) {
+		len = 4;
+		shift = 8 * (sizeof(unsigned long) - len);
+	} else if ((insn & INSN_MASK_C_FLD) == INSN_MATCH_C_FLD) {
+		fp = 1;
+		len = 8;
+		insn = RVC_RS2S(insn) << SH_RD;
+	} else if ((insn & INSN_MASK_C_FLDSP) == INSN_MATCH_C_FLDSP) {
+		fp = 1;
+		len = 8;
+#if defined(CONFIG_32BIT)
+	} else if ((insn & INSN_MASK_C_FLW) == INSN_MATCH_C_FLW) {
+		fp = 1;
+		len = 4;
+		insn = RVC_RS2S(insn) << SH_RD;
+	} else if ((insn & INSN_MASK_C_FLWSP) == INSN_MATCH_C_FLWSP) {
+		fp = 1;
+		len = 4;
+#endif
+	} else {
+		regs->epc = epc;
+		return -1;
+	}
+
+	val.data_u64 = 0;
+	for (i = 0; i < len; i++)
+		val.data_bytes[i] = load_u8((void *)(addr + i));
+
+	if (fp)
+		return -1;
+	SET_RD(insn, regs, val.data_ulong << shift >> shift);
+
+	regs->epc = epc + INSN_LEN(insn);
+
+	return 0;
+}
+
+int handle_misaligned_store(struct pt_regs *regs)
+{
+	union reg_data val;
+	unsigned long epc = regs->epc;
+	unsigned long insn = get_insn(epc);
+	unsigned long addr = csr_read(mtval);
+	int i, len = 0;
+
+	regs->epc = 0;
+
+	val.data_ulong = GET_RS2(insn, regs);
+
+	if ((insn & INSN_MASK_SW) == INSN_MATCH_SW) {
+		len = 4;
+#if defined(CONFIG_64BIT)
+	} else if ((insn & INSN_MASK_SD) == INSN_MATCH_SD) {
+		len = 8;
+#endif
+	} else if ((insn & INSN_MASK_SH) == INSN_MATCH_SH) {
+		len = 2;
+#if defined(CONFIG_64BIT)
+	} else if ((insn & INSN_MASK_C_SD) == INSN_MATCH_C_SD) {
+		len = 8;
+		val.data_ulong = GET_RS2S(insn, regs);
+	} else if ((insn & INSN_MASK_C_SDSP) == INSN_MATCH_C_SDSP &&
+		   ((insn >> SH_RD) & 0x1f)) {
+		len = 8;
+		val.data_ulong = GET_RS2C(insn, regs);
+#endif
+	} else if ((insn & INSN_MASK_C_SW) == INSN_MATCH_C_SW) {
+		len = 4;
+		val.data_ulong = GET_RS2S(insn, regs);
+	} else if ((insn & INSN_MASK_C_SWSP) == INSN_MATCH_C_SWSP &&
+		   ((insn >> SH_RD) & 0x1f)) {
+		len = 4;
+		val.data_ulong = GET_RS2C(insn, regs);
+	} else {
+		regs->epc = epc;
+		return -1;
+	}
+
+	for (i = 0; i < len; i++)
+		store_u8((void *)(addr + i), val.data_bytes[i]);
+
+	regs->epc = epc + INSN_LEN(insn);
+
+	return 0;
+}
generated by cgit-pink 1.4.1 (git 2.36.1) at 2024-09-22 12:17:04 +0000